This review examined preliminary evidence of health behaviour change interventions delivered by mobile telephone short-message service (SMS), concluding that text-message delivered interventions have positive short-term behavioural outcomes, although further research of higher quality in this area is required. Given the potential for bias, the conclusion that SMS-delivered interventions have positive short-term benefits may not be reliable.

MEDLINE, ERIC, Web of Science and PsycINFO were searched for relevant English language publications from peer-reviewed scientific journals published between January 1990 and March 2008. Search terms were reported.

Study selection

Studies were eligible for inclusion in the review if they evaluated an intervention delivered primarily via mobile phone short-message service (or text message) and assessed a change in health behaviour using a pre-post design or a controlled study design.

For each study, the level of mobile telephone short-message service interactivity between researcher and participant was rated as nil, low, moderate, or high, based on the rate of messages sent. Results were classified as having a positive or neutral impact on behavioural outcomes. For studies with a control group, effect sizes were calculated.

Methods of synthesis

Studies were combined in a narrative synthesis.

Results of the review

A total of 14 studies were included in the review (n=3,512 participants). Sample sizes ranged from 10 to 1,705 participants. Eight studies were randomised and six were single group pre-post design studies. Loss to follow-up ranged from 0% to 57%.

Six studies provided sufficient data to calculate effect sizes, which ranged from 0.09 to 1.38. According to Cohen's criteria, two of these studies showed small effects (0.2), two showed medium-sized effects (>0.5), and two showed large effects (>0.8).

Authors' conclusions

Mobile phone text-message delivered interventions appeared to have positive short-term behavioural outcomes, although further research of higher quality in this area is required.

CRD commentary

This review was based on a question broadly defined in terms of the interventions, outcomes, and study designs of interest. Multiple databases were searched to identify relevant studies, and attempts were made to minimise error and bias in selection. However, restricting inclusion to published English language studies may have led to language and publication bias. The use of a narrative synthesis was appropriate given the clear differences between included studies, but counting the number of studies reporting positive results was not an accurate method for evaluating effectiveness. Some aspects of methodological quality were discussed, but the validity of individual studies was not formally assessed. Although the authors' conclusions are appropriately cautious, given the potential for bias among the selected studies, the conclusion that SMS-delivered interventions have positive short-term benefits may not be reliable.

Implications of the review for practice and research

Practice: The authors did not state any implications for practice.

Research: The authors made several recommendations for future research on mobile phone short-message service (SMS) interventions for behaviour change, stating that future studies should: have an adequate sample size from representative populations; report process measures; describe the theoretical constructs being targeted; explore the impact of SMS initiation method and level of interactivity.

This is a critical abstract of a systematic review that meets the criteria for inclusion on DARE. Each critical abstract contains a brief summary of the review methods, results and conclusions followed by a detailed critical assessment on the reliability of the review and the conclusions drawn.